function preload(imgObj,imgSrc) 
{
	if (document.images) 
	{
		eval(imgObj+' = new Image()')
		eval(imgObj+'.src = "'+imgSrc+'"')
	}
}
function changeImage(layer,imgName,imgObj) 
{
	if (document.images) 
	{
		if (document.layers && layer!=null) 
		{
				eval('document.layers["'+layer+'"].document.images["'+imgName+'"].src = '+imgObj+'.src')
				
			}
			else 
			{
				document.images[imgName].src = eval(imgObj+".src")
			}
	}
}